NMR spectral study of two crystalline modifications of lithium metaborate, LiBO2

7Li and11B NMR spectral parameters were obtained for the two structural modifications of lithium metaborate. We first studied the high-temperature γ-form of LiBO2, δiso(11B) ≈ 0, e2qQ/h(11B)=42.5±2.0 kHz, e2qQ/h(7Li)=155±5 kHz. The following values were obtained for monoclinic α-LiBO2 with tricoordination of the boron atom: δiso(11B) = 16±2, e2qQ/h(7Li)=32±10 kHz. The electric field gradient on the7Li and11B nuclei in the different crystal positions was discussed.